Adherence to antihypertensive medication after referral to secondary healthcare: A prospective cohort study

BACKGROUND: Nonadherence (NAd) to antihypertensive medication is associated with lack of blood pressure control and worsened long-term outcomes. Increased access to a programme for high-risk cardiovascular patients has the potential to reduce NAd and improve clinical outcomes. We evaluated implementation NAd prevalence and risk factors among severely hypertensive patients after 12-month-long access to secondary healthcare centres. METHODS: The Morisky Green Levine Scale (MGLS) was used to analyse antihypertensive medication NAd in a prospective cohort of 485 patients. Logistic regression models evaluated the influence of ecological model factors on NAd. RESULTS: The majority of patients were female, had low health literacy, a low family income and a mean age of 61.8 ± 12.5 years. Prevalence of NAd fell from 57.1% at programme entry to 28.3% (P < .001) at the end of the study. After access to a secondary healthcare centre, we observed better blood pressure control, an increase in the number of pills/day and a higher number of antihypertensive medications. Predictive variables of NAd were age (OR 1.027; CI 1.003-1.051; P = .023), low health literacy (OR 1.987; CI 1.009-3.913; P = .047), systolic blood pressure (OR 1.010; CI 1.003-1.021; P = .049), dosages ≥ 2 times/day (OR 1.941; CI 1.091-3.451; P = .024) and patient satisfaction with the healthcare team (OR 0.711; IC 0.516-0.980; P = .037). CONCLUSIONS: Greater access to health services is associated with a reduction in NAd to antihypertensive medication and better blood pressure control. NAd was correlated with modifiable variables such as treatment complexity and, for the first time, team satisfaction, suggesting that implementation of similar programmes may limit NAd in similar patient groups.